Combined oil and vacuum pump



vPatented Dec. 1, 1925.

UNITED STATES P.STTENT OFFICE.`

CLIFFORD C. BRADBURY, OF OAK PARK, ILLINOIS, .ASSIGNOR, BY MESNE ASSIGNMENTS,

TO CURTIS IB. CAMP, TRUSTEE, OF OAK PARK, ILLINOIS.

COMBINED on. AND VACUUM PUMP.

Application tiled October 31, 1921. Serial No. 511,871.

To all whom it may conce/m.'

Be it known that I, CLIFFORD C. BRAD- BURY, a citizen of the United States, and resident of Oak Park, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Combined Oil and Vacuum Pumps, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to a combined oil and vacuum pump, for the oil circulating system of an automobile, and for supplying suction for the suction operated devices of the automobile, such as the vacuum tank,

windshield cleaner, tilting headlights, and' the like.

One object of my invention 1s to secure,

through the combination of the oil pump and the vacuum pump, the automatic oiling of the piston and cylinder of the vacuum pump.

Another object of my invention is an improvement in the operation of the oil pump which prevents it from becoming air bound.

Other objects of my invention reside in the details of construction hereinafter more fully described.

My invention is illustrated in the accompanying drawings, in which-- Figure 1 is a section through a crank case Wall, and throughV the combined oil and vacuum pump;

Figure 2 is a layout of a vacuum system for supplying uel to a carburetor, showing the method of connecting the system with the vacuum duct extending from the pump.

.The pump. housing 3 extends ,into the crank case through the wall 4 at'a posit-ion adjacent the engine cam shaft 5, on which a cam 6 is mounted for reciprocating the pump pistons. The casing 3 is provided with two axially arranged cylinders 8 and 9, the latter being of a little more than twice the cross-sectional area of the former. A piston 10 is arranged for reciprocation within the cylinder 8, and is spring pressed inwardly -by a compression spi-in 11, the piston 10 being preferablycuppe to form a seat for the spring. A pipe 13 connects from a point below the oil level in the crank case past the valve 14 with the space at the head of cylinder 8. A second valve 15 controls the entrance to the oil discharge pipe 16, the arrangement being such that the reciprocation of the ypiston 10 pumps oil through the pipe 13 and discharges it from the pipe 16, whence it is led in the usualv mlnner to the parts ofthe engine requiring o1 The piston 18 is fitted within the c linder 9, and is pressed inwardly toward t e .cam 6, by contacting with the end of the piston 10. The space at the head of cylinder .9 communicates by way of a valve 19 with the suction line 20. Within the piston 18 is a second valve 21 controlling the discharge from the space at the head of the cylinder 9. The va ve 21' is seated upon a threaded seat 22, which communicates with the space at the head of the cylinder 9 through a slot 23 cut cross-wise in the lower end of the piston 10. The space on the crank case side of the valve 21 communicates with the crank oase through a duct 24.

YIn operation, the rotation of the cam shaft 5 causes the pistons 18 and 10 to move outwardly against the pressure of the spring 11. This movement ejects the oil from the head of the cylinder 8 past the ball valve 15 and also ejects the air from the space at the head of cylinder 9 past the'ball valve 21 and into the crank case. As the cam continues its rotation, the spring 11 forces the pistons 10 and 18 back to their illustrated position,causing oil to be drawn past the valve 14 into the space at the head of cylinder 8, and causing air to be drawnl from the suction line 20 past the valve 19, and into the space at the head of cylinder 9. Under some operating conditions, as for example when the suction port in the fuel tank 26 is closed, the suction produced in the chamber at the head of cylinder 9 will be much greater-than the` suction produced in the space at the head of cylinder 8. This piston 18, but if more'oil is drawn than is4 necessary rfor lubrication, lthe surplus will be ejected along with the air past the valve 21.

An air bound oil resultsprimarily because of the fact t at the oil in the crank case of the engine and in the pipe leading therefrom to the pump becomes so viscous from cold that it does not readily iow. Ordinarily, when .this condition arises, the suction within the oil pump draws air from the crank case past the oil pump piston, and into the oil pump. With ya certain amount of air in the oil pump, the reciprocation of the piston serves only to compress and'expand this air, and the suction produced on i the pipe leading to the pump from the crank i' case is insufficient to` move the oil stiened by cold. By means of my invention, however, the air is extracted from the oil pump chamber through lthe, high suction produced A mounted in the'respective cylinders, there being a s uiiicient space between the oil piston and its cylinder for the passage of a small amount of oil, passage means/for said small amount of oil to the air cylinder, whereby the latter is lubricated, and a reservoir into which the excess oil passesfrom said air cylinder.

2. In a combined oil and vacuum pump,

thev ycombination with a housing having a pair of axially' aligned cylinders formed therein, the area of cross-section of the larger cylinder being more than twice the area of cross section of the smaller cylinder, a pair of pistons, one for each vof said cylinders, a spring pressing the small piston against the large piston, an engine crank case, a cam therein for moving the large piston and the small piston against the pressure of said lspring, a 'pairof valves controlling the low to and from the space at the head of the small piston to pump oil, and a pair of valves controlling the iow to and from the I space at the head .of the large piston to pump air, and a communication past one of` '3. A device for attachment to an' engine crank case, -Said device having a pair of cylinders therein, a pair of pistons in said cylinders, a cam shaft within the crank case adapted in its rotation to cause the reciprocation of said pistons, onev of said pistons serving to pump oil for the lubrication of the engine, and the other of said pistons serving to pump air to create a suction for the operation of a suction operated device and a valve, past which the pumped air discharges into the crank case.

4. A device for attachment to the crank case of an internal combustion engine, a cylinder in said device, a piston within said cylinder, a cam shaft within the crank case having a cam thereon` for operating said piston in one direction, a spring for operating said piston in the other direction, a connection leading out of said cylinder` and discharging into the crank case, avalve in said 'connection permitting flow in the direction toward the crank case only, a connection leading Vinto said cylinder and extending to lsuction operated apparatus, the reciprocation of said piston serving to pump air to create a suction for lthe'operation of said apparatus and means forming a lubricant receptacle in communication with said cylinder, said device permitting the circulation of lubricant from said receptacle past the piston of said'.

pump. f A

5.v The. combination with means forming an oil circulating system including a pump comprising a first cylinder, a piston therein, valves for the pump, and means for reciprocating said piston, of a pneumatic suction pump comprising a second cylinder, a second piston therein'moved with the lirst piston,

and valves for the suctionvpump, the first cylinder communicating with the second cylinder past the first piston to permit oil to pass into -the'second cylinder to lubricate the second piston, and means for leading the oil from the. second cylinder back into said circulating system.

In witness whereof, I hereunto subscribe my name this 29th day of October, 1921.

f CLIFFORD C. BRADBURY. 

